I was watching the Giants-A's game tonight and they were talking about a balk that was called in last night's game that they didn't understand. Dave Flemming recounted his discussion with Bill Miller before the game and said that it was a point of emphasis this year.
I can't find a video online about it. Chris Bassitt is in the stretch, foot on rubber. Brings his hands together. Then, he steps back with his front foot (Lefty, he moved it towards 3B), then delivers the pitch. It's almost like he goes into a windup after he's come set.
Here's a video with Price, but he moves it forward, then goes into his delivery.
http://m.mlb.com/video/v568503883/bospit-price-fans-five-holds-pirates-to-one-run
I can't recall ever seeing a pitcher do this in MLB.